Objective—To evaluate plasma taurine concentrations
(PTC), whole blood taurine concentrations
(WBTC), and echocardiographic findings in dogs fed 1
of 3 protein-restricted diets that varied in fat and L-carnitine
Animals—17 healthy Beagles.
Design—Baseline PTC and WBTC were determined,
and echocardiography was performed in all dogs consuming
a maintenance diet. Dogs were then fed 1 of
3 protein-restricted diets for 48 months: a low-fat (LF)
diet, a high-fat and L-carnitine supplemented (HF + C)
diet, or a high-fat (HF) diet. All diets contained methionine
and cystine concentrations at or above recommended
Association of American Feed Control
Officials (AAFCO) minimum requirements.
Echocardiographic findings, PTC, and WBTC were
evaluated every 6 months.
Results—The PTC and WBTC were not significantly
different among the 3 groups after 12 months. All
groups had significant decreases in WBTC from baseline
concentrations, and the HF group also had a significant
decrease in PTC. One dog with PT and WBT
deficiency developed dilated cardiomyopathy (DCM).
Taurine supplementation resulted in significant
improvement in cardiac function. Another dog with
decreased WBTC developed changes compatible
with early DCM.
Conclusion and Clinical Relevance—Results
revealed that dogs fed protein-restricted diets can
develop decreased taurine concentrations; therefore,
protein-restricted diets should be supplemented with
taurine. Dietary methionine and cystine concentrations
at or above AAFCO recommended minimum
requirements did not prevent decreased taurine concentrations.
The possibility exists that AAFCO recommended
minimum requirements are not adequate for
dogs consuming protein-restricted diets. Our results
also revealed that, similar to cats, dogs can develop
DCM secondary to taurine deficiency, and taurine supplementation
can result in substantial improvement in
cardiac function. (Am J Vet Res 2001;62:1616–1623)